The present invention relates to torque sensors. More particularly, the invention relates to a torque sensor that magnetically measures the torque applied to a set of shafts, most typically in an automotive steering system.
A torque may be measured in a system that has an input shaft and output shaft and a compliant shaft or torsion bar that connects the two shafts. A magnetic sensor is fitted on or placed at the interface of the two shafts. The sensor may include a magnet, a stator, a collector, and a magnetic sensing element. The torsion bar has a known spring constant or torsional rigidity. Rotational movement of the input shaft with respect to the output shaft produces a relative angular displacement between the two. The angular displacement is proportional to the torque exerted on the input shaft (such as by a person turning a steering wheel). The angular displacement is then measured using known magnetic principles.